For example, an integrated coal gasification combined cycle facility is a power generation facility which gasifies coal and is combined with combined cycle power generation for the purpose of an increase in efficiency and higher environmental properties compared to conventional coal-fired thermal power. It is known that the integrated coal gasification combined cycle facility has an advantage of using coal which is an abundant resource and has a further advantage through expansion of applied coal types.
A conventional integrated coal gasification combined cycle facility generally includes a coal feeding apparatus, a drying apparatus, a coal gasification apparatus, a gas refining apparatus, a gas turbine facility, a steam turbine facility, a heat recovery steam generator, a gas purifying apparatus, and the like. Therefore, coal is crushed after being dried and is supplied to the coal gasification apparatus as fine coal, and air is supplied so that the coal is turned into combustion gas by the coal gasification apparatus, thereby producing product gas (combustible gas). In addition, the product gas is refined and is supplied to the gas turbine facility to be burned. As a result, high-temperature and high-pressure combustion gas is produced to drive turbines. Exhaust gas after driving the turbines is subjected to thermal energy recovery by the heat recovery steam generator. Subsequently, steam is produced and is supplied to the steam turbine facility to drive turbines. Accordingly, power generation is achieved. On the other hand, the exhaust gas from which thermal energy is recovered is subjected to removal of harmful substances by the gas purifying apparatus, and is thereafter emitted to the air via a stack.
By the way, the coal gasification apparatus includes a gasification furnace and a heat exchanger (gas cooler). The gasification furnace burns the supplied coal (fine coal) using compressed air (oxygen) to turn the coal into gas, thereby producing combustible gas (coal gas). The heat exchanger cools the combustible gas produced in the gasification furnace. The gasification furnace and the heat exchanger are generally installed to be adjacent to each other, and the combustible gas produced in the gasification furnace is sent to the heat exchanger through a pipe and is cooled.
However, separately installing the gasification furnace and the heat exchanger as the coal gasification apparatus and connecting the two by the pipe lead to problems in that the overall structure is increased in size and the installation cost is increased. As a solution to the problems, there is a coal gasification apparatus described in Japanese Patent Publication No. 61-221294 as follows. In the coal gasification apparatus described in Japanese Patent Publication No. 61-221294, a heat exchanger is directly formed on the upper portion of the gasification furnace to be continuous.